Spinning and roving frame



Oct; 21, 1941. J. H. ARMSTRONG E'QI'AL I 2,260,130

SPINNING AND ROVING FRAME Filed Feb. 15, 1940 g .14 INVENTORS;

, tion.

Patented a. 21, 1941 John H. Armstrong and Roderic Maine, assignors to Saco-Lowell Shops,

Mass., a corporation of li iaine V ford, Boston,

1). Torr, Bidde- Application February 15, 1940, Serial No. 319,032

5 Claims. 01. 19-430) understood from the following This invention relates to the drawing mechanisms of spinning and roving frames. Such mechanisms are customarily used in machines of this type to exert a parallelizing action on the' fibers and to reduce the cross-sectional dimensions of the sliver or roving to that suitable for the particular product to be made. Usually these mechanisms consist merely of a series of pairs of upper and lower rolls arranged in line so that they act successively on one or more strands of fiber, each pair of rolls being driven at a higher speed than the preceding pair.

All of the bottom rolls are made of metal and consist of long shafts extending the entire length oi the frame and provided at suitable intervals with fluted bosses for engaging and feeding the strands of roving. The top rolls, however, are short, each usually having two bosses connected by a reduced neck. The bottom rolls are positively driven by gearing at one end of the frame while the top rolls are revolved merely by contact with their respective bottom rolls. Usually, also, the top rolls are covered with a yielding material, such as leather, cork, or some synthetic composi- It was discovered some years ago that if the back line of top rolls were-made of a metallic fluted construction so that they would intermesh with the flutes of the bottom roll and thus be positively driven by the latter, such rolls, under some conditions, exerted an evening action on the strands of roving. In attempting to take advantage of this very desirable action, it was found that if the rovings were traversed axially of the rolls in the customary manner in order to distribute the wear on the top rolls having covers of leather or other yielding material, the evening action of the intermeshing back rolls disappeared and usually was replaced by a tendency to increase the initial irregularities in the roving. For this reason metallic feeding rolls or back rolls have never gone into commercial use to any substantial degree, so far as we have been able to learn, in drawing mechanisms of the type above referred to.

The present invention aims to overcome these difllculties and to utilize the advantages of intermeshing metallic back rolls in spinning and roving frames, both to effect an evening action on the sliver or roving and also to assist in producing a better control of the drafting operation, while at the same time traversing the fibrous strands axially of the rolls sufficiently to distribute wear to the desired degree.

description when read in connection with the accompanying drawing, and the novel features will be particularly pointed out in the appended claims.

In the drawing;

Figure 1 is a diagrammatic view with some parts in elevation and some in vertical. section showing a drawing mechanism for a cotton spin ning or roving frame embodying features of this invention;

Fig. 2 is a fragmentary, sectional view on a large scale showing the relationship between the upper and lower rear rolls; and

Fig. 3 is a front elevation of an upper rear roll and the section of the lower roll cooperating therewith.

Referring first to Fig. 1, a drawing roll arrangement is there shown which is of a common type except for the fact that the rear rolls are of novel form. This arrangement includes upper and lower front or deliver! rolls 2 and 3, middle rolls 4 and 5, and corresponding rear rolls or back rolls 6 and I. The roving or sliver 9 is led from any suitable source of supply through a' trumpet 8 to the bite of the rear rolls and then passes forward through the other rolls of the set. Usually, the middle rolls are driven at a somewhat higher speed than the rear rolls and the delivery rolls 2 and 8 revolve at a considerably higher rate than the middle rolls. This is a common roll arrangement, but the number of pairs of rolls used vary 1 with different types of mechanisms, and one or more of the intermediate rolls sometimes is re- 'placed with an equivalent device, such as a belt or apron. So far as these features of general organization are concerned, the present invention requires no change in any of the drawing mechanisms customarily used in cotton spinning and roving frames except that the rear line of upper and lower rolls is replaced with fluted intermeshing rolls such as those shown in Fig. 3.

The lower of these rear rolls consists of a. long shaft, similar to those in, common use, provided with a series of fluted bosses spaced apart by suitable distances. In this instance the bosses are of a novel form. That is, they'are grooved more deeply than is customary and each boss is divided into two sections, one section ll, Fig. 3, having teeth longer in radial dimensions than those in the adioiningsection II.

The top roll 8 also is similar in its general form tothose customarily'used but differs from them The nature of the invention will be readily manner as the lower l l the latter,

each boss is divided into two sections l3 and as, the teeth in the latter section being shorter than those in. the former.

As shown in Fig. 3, the teeth or each section 353 of the lowerroll inter-mesh with those of the corresponding sections it of the upper roll. Since theformer is positively driven, as above explained, this arrangement also prosltlvely drives the upper roll. These sections are utilized solely ior driving purposes and they do not normally engage the silver or roving. The sections is and id of these rolls, however, are provided for :dber feeding purposes, the sliver being fed between these areas by the engagement oi the teeth with it, as shown in dig. 1. In these areas, however, the teeth are so reduced in radial dimensions that they are never in contact with each other even when there is no fiber between them. in the particular construction shown this result is accomplished by grinding or machining the sections it and it down to approximately the pitch circle,

preferably so that some clearance is left between the tops of the teeth at all times, even when the driving teeth of the two rolls bottom one in the other. Such clearance may be only very slight,

- say, in the neighborhood of threeor fourthousandthsoi an inch. This arrangement is illustrated on a considerably enlarged scale in Fig. 2, the pitch circles being shown in broken lines, the teeth in the fiber working sections l2 and H appearing in cross-section and the tops of the longer driving teeth oi the sections it and 13 being shown in elevation.

In the particular construction shown a novel fluting has been used The teeth of the bottom roll are of involute form while those of the top roll are of a more rounded formation. In this construction a typical radius for the groove between the meth of the bottom roll is .0375" and the total tooth height or radial dimension from root to tip is in the neighborhood of .062". Such a roll usually is about an inch and an eighth in outside diameteriu the section 10. In the top roll the tooth height is somewhat shorter, say .051" and the radius of the groove separating adjacent teeth is about 1042". Usually the number of flutes per roll is between and 40. While this construction is one that has worked well,

it has'been foundthat the shape of the teeth may vary considerably while producing entirely satisfactory results. In fact, the common form of fluting gives good results if deepened slightly and suitable clearances are provided. A form of tooth more like that shown in the drawing is preferred, however.

These rolls are mounted in the usual manner, the lower roll being supported in the bearing sockets provided for it in a roll stand, and the upper rolls being held in the proper relationship to each other and to the bottom rolls by means of the usual cap bars. Also, the top rolls are weighted in some suitable or customary mannor as, for example, by means of weight hooks, each equipped with a saddle element bearing on the neck portion 01 the top roll. Such a hook and saddle are indicated at 15 and I6, respectively, Fig. l, and the saddle is shown at It in Fig. 3.

With this arrangement the top roll rides on the two strands or silver being fed between the sections Hl l and the bottom roll, and it rises and falls to accommodate variations in the thickness of successive portions of the strands. However, it is so weighted that the flutes of the top roll force the sliver more or less into the grooves aaoonso of the bottom roll. The amount of cotton so pressed into the flutes appears to be nearly constout regardless of variations in thethlckness leveling action on the sliver so that they feed to the rolls in front of them a more uniform weight of cotton per revolution of the bottom roll than they receive- Such a reduction in yard for yard variation in the product is an important advantage.

The drive from the lower to the upper roll normally takes Place through the cotton but if any slip tends to occur it is stopped almost instantly by the action of the driving teeth. Consequently, the feed is positive and the fiber feed ing teeth of the two rolls can never get materially out of correct angular relationship to each other. Vt'hile this relationship is not one of actual intermeshing because the teeth are not long enough to mesh, or at least not to any substantial degree, still that relationship is of advantage from an operating standpoint. It will be observed that the long teeth of the two rolls provide, in effect, a geared connection between ill) the rolls and that the limited clearance between the teeth aiiords a certain diflerential or comeand-go in the driving connection necessary to enable the rolls either to drive or to hold, as may be necessary. Y Closely related to this operation is the fact that the engagementof the two sets of teeth with the sliver at the feeding point effectively holds the fibers against any material degree of slip. When a, cushion top roll cooperating with a fluted bottom roll is used in the back line of the drawing mechanism and the draft between the middle and back rolls is of substantial value,

then it is necessary to weight the top roll very heavily in order to prevent some slip. The arrangemezit here provided, however. prevents such an action even with a relatively light weighting and produces a positive feed. Since an evening action is coupled with this positive feed, as above described, the operation of the entire assembly is improved and a yarn having a higher average breaking strength is produced.

A typical weighting applied to the neck of the roll his in the neighborhood of ten or twelve pounds. In some cases it may be reduced as low 1 as live or six pounds and it practically never runs above twenty pounds.

Such an arrangement as that above described works well with the ordinary traverse mechanisms in which both strands running under a given top roll are simultaneously moved axially oi the rolls first in one direction and then in the other. With the old arrangements such a traverse set up a leverage condition which resulted in a very substantial variation in the weight applied to any strand at diflerent points in its stroke. ,That is. thestrand nearest to the neck oi the roll always was under a greater This leverage condition is minimized in the arrangement above described because the outer ends ofthe top roll are in driving engagement with the or scope thereof.

V 2,260,130 bottom roll, and the approach of eitherend of the top roll to the corresponding portion of its both also having cooperating fluted flber feeding areas in which the teeth are spaced circumferentially to intermesh but are so reduced in height companion lower roll] is limited by] the driving that they are always held out ofintermeshing teeth of the lower roll bottoming in the grooves or the driving teethoithe toproll. Thus'the greater part of the dimcultyr which has v been experienced heretofore in using-intermeshing -metal rear rolls in a drawing mechanism of this type together with 'atraverseimotion is obviated. V

In addition to the particular arrangement above described it' should'be understood thatgood results can be obtained with slightly diiferfound desirable in operating on different weights relationship by the driving teeth of the two rolls,

I said teeth in the flber feeding areas of the rolls being high'enough so that those of one roll force the roving into the grooves of the other roll during the feeding action of the two rolls.

3. In a drawing mechanism for roving and spinning frames. the combinationwith a set of ent relationships of the fluted rolls to each other 4 and some variation in this relationship will be drawing rolls, of a pair of inter-meshing fluted upper and lower rolls, the lower of which is driven, positioned behind the drawing'rolls where and-compositions of sliver. For a cotton sliver of the common staple lengths and weighing from fifty to sixty grains per yard, the spacing of the rolls 6 and I may'vary from a clearance of -.006 inch to an intermesh of '.010, inch while still producing good results.

It-will-be obvious to those skilled 'in this art" cooperate with each pair 0': bosses of the-lowerroll.

.While we have herein shown and described a typical embodiment of'our invention, it will be evident that the invention-may be embodied in 3 from the spirit other forms without departing Having thus described desire to claim as new is:

our invention, what-we they serve, to feed the roving to the drawing rolls, said fluted .rolls having inter-meshing teeth to drive the top roll from the bottom roll and both also having cooperating fluted fiber feeding areas in which the teeth have the same pitch as the driving teeth but have their tops cut down to approximately the pitch circle,

whereby the roving is crimped and gripped by the flutes of said fiber feeding areas of the rolls.

4. In a drawing mechanism for roving and spinning frames, the combination with a set of drawing rolls, of a pair or fluted upper and lower rolls, the lower of which is driven, positioned behind'the drawing rolls where they serve to 1,. In a drawingmechanism for-roving and spinningframes, the combination witha set of drawing rolls, of a pair of fluted upper and lower rolls meshing with each other and positioned behind the drawing rolls where they serve to feed the roving to the drawing rolls, said fluted rolls having intermeshing teeth to drive the top roll from the bottom roll and also having fluted'flber feeding areas in which the teeth are shorter in radial dimensions than said driving teeth and are positioned in angular relationship suitable for intermeshingwith each. other but are held at all times out of direct contact with each other, 1

feed-theroving to the drawing rolls, said fluted rolls having intermeshing teeth to drive the top roll from the bottom roll and both also having cooperating fluted flber feeding areas in which the teeth are cut down to approximately the pitch circle and havingsuflicient-clearanceso that the top roll is normally driven through the intervening roving, and weighting means for said top roll for-applying apressure thereto ofhetween five and twenty'pounds.

5. In a drawing mechanism for roving and spinning frames, the combination with a set of drawing rolls, of apair. of fluted upper and lower rolls, the lower roll of which is driven,- positioned behind the drawing rolls where they serve to feed the rovingvto the drawing rolls, said fluted rolls having intermeshing teeth to drive the top roll from the bottom roll and both also having cooperating fluted-flber feeding areas in which the teeth are cut down to approximately the'pitch circle but are so spaced circumferentially that they would intermesh if theywere of suficient length to do so, whereby they crimp the roving fed' through them, means supporting said top drawing rolls, of a pair of intermeshing fluted upper and "lower rolls, the lower of which is driven, positioned behind the drawing rolls where they serve to feed the roving to the'drawing rolls, saidfluted rolls having intermeshing teeth to drive the top roll from the bottom roll and roll for vertical movement toward and from its companionlowenroli, and'means for pressing the top roll yieldingly toward the bottom roll withv suflicient pressure to grip and feed strands of rovingbut yieldingvertically with changes in 1 the thickness of successive portions of the roving;

JOHN H. ARMSTRONG.- RODERIC n. TARR. 

